Went to the pick your part today and found a 1965 t-bird with a 390. Pulled the heads, rocker shaft assembly, pushrods, and intake manifold to install on my 360.
My current heads are C8AE-H
My current intake is stock 2v

New parts are:
Heads: C4AE 6090G
Intake: C5AE 9425C
The intake is a 4v which will get a Holley 650 double Pumper.
The 6090G heads have larger ports and bigger combustion Chamber volume. Will there be any problem with this swap? Will I get any increase in HP, torque? Any down side to this swap? Thanks.
Jay

 

Jay, There are other guys much brighter than me, that will jump in & help, but I believe you have high value parts & might want to go back and get the rest of that engine.

Let's see what the others say.

Forget the D-pumper unless you are racing. Way too much carb for the truck.


John

 

you should have grabbed the whole engine !
heads & intake straight bolt on ( heads should get hardned seats )
double pumper not a good choice for these heavy trucks , switch to a vacuum secondary if you can .

 

360 and. 390 are the same block. Should theoretically bolt up. I'm in agreeance with John..650 vac secondary would be ok..but a double pumper is way too much. I would also go back and see what else you can get..they built the car motors to go fast..so a 390 truck and a 390 car engine behave differently..hence the heads and intake you found

 

yup tbird 390 should have like 9:1 or 9.5:1 CR

measure the valves , if i remember right the 6090 had larger valves .

 

By all means go get the rest of that motor! You might could've gotten the whole engine for close to what you paid for the heads and intake. Definitely need hardened seats and I would buy new pushrods and lifters. When you and all your close friends and relatives get ready to remove and install the intake, use some Right Stuff on the ends of the manifold for a good seal.

 

You've heard it from the world..you done did good! Now go get the rest haha I'm excited for you

 

I agree with everybody above! Son, go back and get the rest of that motor and build it. For two reasons. 1st, 390's are torque monsters. We all love pedal to the metal and smashing the back of our seats. 2nd,the bigger combustion chambers with your pistons will lower compression ratio. More space to fill lowers the ratio of how much your pistons can compress. Trust me, don't do it Al Carte. Buy the whole meal!

 

this might help you some
Ford "FE" Engine Specifications

 

AWESOME link! Thx Mon!

 

I agree to a certain point. We have pickupart here and half price day a full carb to pan is like 157.00 iirc. Been there done that. The 67' F100 truck I got my 4Vintake from had a builder tag and fresh 390 with cyl hone marks!!! 4speed toploader!!! Fresh heads.. I chose to come back later with a helper!, BIG F UP! all gone.....

Had to be a ex-wife come and get it special!! Not a dent in it!! But I have drug home parts that wern't worth a crap too.. dig in first. Carb to pan in a pile is carb to pan!!

 

Hold on!

The intake will work ok, but check it for port mismatch. Probably OK.

The carb: Double pumper is not what you want, see previous posts, or search Holley or other fine brand web sites for "how to pick a carb" or similar.

The heads: You say they have larger combustion chambers than your current heads? Have your measured them? IF they are bigger, you are looking at even lower compression than your current pathetic 8.2, and a reduction in torque and probably horsepower. (You might be able to rev it higher, regaining some HP, but this would be a big unknown)

The 360 suffers a sunken piston, and no head change will fix that. Larger CC's will just make this worse, and not in a good way....

Now, the '65 T-bird motor is going to be a 10.1 CR if stock. Cam wise, it may be a bit better than the 360, but stock it's pretty much all done before 5000 rpms, with peak power at 4500. This is mainly due to the exhaust manifolds.

Serving suggestion:

--get a vacuum secondary 600 or 650 4bbl

--install that with your new manifold

--forget the heads

--install a set of headers.

Until you fix the compression--which requires a piston change* if not a change to the 390 car rotating assembly--and cam it up, those heads are going to hurt, not help.

*.060 or so 352 pistons will work, if you can find them and if your 360's bore will take them at only .010 over

 

PER my link
the 64 heads should have 72-74 cc
68 c8ae-h should be 72cc (same heads i have)

if you are getting heads rebuilt you can shave off some meat and bring the cc down , as for intake to heads if they came off same engine they should match up . if you have heads shaved be sure to have them shave intake to match if need be

 

Ok, much thanks for all the input. I removed the stock heads from the 360 yesterday and as we thought (see previous post on 360 low compression in #1 cylinder), my #1 ex valve was burned and had a hole in it. So I am going to swap heads. My 360 has pistons with with recessed valve slots in the top not flat top type. The look exactly the same as the 65 t-bird pistons. I am hoping to God that means I have a higher compression 360 then what has been posted. I'm short on cash and can't afford to mess with the bottom end right now. I just want to get my truck running again. Can some one explain the process of determining compression ratio to me? When I test compression on the stock 360 before head removal I was getting 135-140 readings at all other cylinders. That seemed higher then 8.5 to 1, right??

 

problem is the 360 piston sit lower in cylinder at TDC you will see wear mark on cylinder (shiny/dark)